declare const hdm: {
    getUser: () => HDMUser
    showMessage: (msg: string) => void
    takePicture: () => string
    selectPicture: () => string
    takePictureBase64: () => string
    takePictureBase64: () => string
}
// 给hdm对象声明一个类型 当使用这个全局对象的时候会有提示

